Makindo Medical Notes.com

Related Subjects: |Fractured Neck of Femur |Fractured Shaft Femur |Supracondylar Femur Fractures |Femoral fractures and Injuries

Intracapsular fractures have a higher incidence of AVN and non-union due to the femoral head blood supply. If displacement is minimal, internal fixation gives the best outcome. In displaced fracures tehre is a high risk of AVN so the head is excised and a prosthesis inserted.

About

• Intracapsular fractures are at risk of AVN
• 30% will die within 1 year.
• Fracture is seen most commonly int th elderly
• Most due to instability and osteoporotic bone.
• Patients often have multiple co-morbidities

Epidemiology

• 80,000 Hip fractures per year in UK
• Increasing number as population rises

Anatomy

Aetiology

• Falls, Osteoporosis
• The medial femoral circumflex artery is at high risk of compromise in neck of femur fractures (NOF#).
• A femoral neck fracture can compromise the flow in this artery due to its close proximity to the femoral neck, leading to an ischaemic injury and subsequent necrosis known as avascular necrosis.

Risk factors for bone fragility

• Osteoporosis: Age, Inactivity, Current smoking, Excessive alcohol intake, Low BMI <18.5, Heredity, Previous osteoporotic fracture doubles their risk of a further fracture
• Metastases, Paget's disease, Osteomalacia, Hyperparathyroidism, Myeloma

Risk factors for falls include

• Muscle weakness, Abnormalities of gait or balance
• Neurological disease e.g. Parkinson's disease, stroke
• Poor visual acuity, Drug therapy: sedatives, hypnotics, diuretics, antihypertensives, Alcohol, sedation

Clinical

• Pain and External rotation, adduction, & shortening of the affected leg.
• Check history - simple explained fall or medical causes
• If presyncope/syncope exclude postural hypotension, cardiac arrhythmia.
• Identify co-morbidities which may influence patient management

Types of Fracture: in relation to the joint capsule

• Intracapsular fractures there is a risk of non-union and avascular necrosis. Treatment is a hemiarthroplasty but for some, a total hip replacement may give better results though this is unproven.
  • Subcapital fractures
  • Transcervical fractures
• Intracapsular hip fractures can be graded according to severity using the Garden classification system. There are four grades of severity:
  • I - Incomplete fracture.
  • II - Complete fracture (across the femoral neck) that is undisplaced.
  • III - Complete fracture that is partially displaced.
  • IV - Complete fracture that is totally displaced
• Extracapsular fractures:
  • Trochanteric fractures
  • Transtrochanteric fractures
  • Subtrochanteric fractures
• Other fractures that can occur with this mechanism are
  • Fractures of the pubic ramus:managed conservatively
  • Fractures of the acetabulum:managed conservatively

Investigations

• FBC, clotting, U&E, CXR, ECG, crossmatch 2U, consent.
• AP Pelvis: Plain Film should be done if any suspicion of a fracture. Ask for AP pelvis. Shows both hips for comparison and will also show other fractures (eg pubic rami) that may also occur in a fall. Lateral of the hip. This is essential as not all fractures will show on an AP X-ray. The neck of the femur will be at right angles to an AP X-ray when the hip is in about 100 of internal rotation. If the hip is externally rotated, the neck of the femur may appear foreshortened and this may make fractures less easy to see. If there is doubt on these X-rays as to the presence of a fracture, an AP X-ray centred on the hip may be of value.
• CT/MRI scan can help if uncertain of fracture or anatomy. Less than 10% can have X ray negative fractures.

Prevention

• Multidisciplinary, multifactorial health/environment risk factor screening and intervention programmes
• Muscle strengthening and balance retraining, Home hazard assessment and modification. Withdrawal of psychotropic medication. A 15 week Tai Chi group exercise intervention
• Even if falls are reduced, lack of evidence that fractures are reduced.
• Bisphosphonates have been shown to increase the bone density in the hips and to reduce the incidence of hip fractures.
• Supplementation of calcium and vitamin D and hormone replacement therapy have been shown to reduce the incidence of fractures.
• Initial research indicated that hip protectors were of value in preventing hip fractures but more recent evidence suggests that this is not the case. [7]

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The 30 day in-hospital mortality varies in different series (8-13%) but is probably about 10% though only about half is caused directly by the fracture. The 12-month mortality is about 30% and this largely reflects co-morbidity.

Management

• ABC, Analgesia, IV Fluids. Orthogeriatrics involvement. Fascia iliaca compartment block
• Give analgesia and try to mobilise the patient. If the patient walks well, there is no fracture and they can be discharged. If the patient cannot walk they will need admission
• Try again to mobilise the patient the following day: if they are still immobile, they will need further imaging to exclude an occult fracture. The best form of imaging to exclude a fracture is an MRI or CT. If it is not possible to obtain an MRI, CT scan or a bone scan may be performed or further plain films obtained after 48 hours
• Pressure sore risk, Hydration and nutrition, Fluid balance, Pain and pain management. Pressure-relieving mattress, look for other injuries and medical problems. Pain relief, Immediate fluid resuscitation with intravenous saline.
• Core body temperature using a low reading thermometer. Continence, Coexisting medical problems.
• Mental state: Depression, delirium, dementia. Previous mobility, Previous functional ability. Social circumstances and whether the patient has a carer
• Surgery
  • Intracapsular fracture: Undisplaced:cannulated hip screw. Displaced: (hemi)arthroplasty or THR if normally ambulant & medically fit
  • Extracapsular: cannulated hip screw
• VTE prophylaxis: should be started at admission using (based on individual patient factors) and may include anti-embolism stockings (thigh or knee-length), foot impulse devices, intermittent pneumatic compression devices (thigh or knee-length). And this should be continued until the patient no longer has significantly reduced mobility. Other choices are DOACS, LMWH, UFH for patients with renal failure), and Fondaparinux sodium, starting 6 hours after surgical closure. It should not be used pre-operatively because of the risk of an epidural haematoma if the patient had an epidural or spinal anaesthetic.

References

• RCEM learning on this